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Water Use in Global Livestock Production—Opportunities and Constraints for Increasing Water Productivity
- Jens Heinke
- Mats Lannerstad
- Dieter Gerten
- Petr Havlík
- Mario Herrero
- An Maria Omer Notenbaert
- Holger Hoff
- Christoph Müller
-  20 November 2020
Key Points
- Annually, 4,387 km3 of water is required to produce the feed consumed by the global livestock sector, of which 94% is green water
- Opportunities for increasing livestock water productivity exist for all livestock types but are particularly large for ruminants
- Water productivity improvements for ruminants through supplementation with feed crops are constrained by high water cost to produce crops
Open accessDiurnal Pumped‐Storage Operation Minimizes Methane Ebullition Fluxes From Hydropower Reservoirs
-  20 November 2020
Key Points
- Draw down associated with turbination during pumped‐storage operation triggers ebullition in reservoirs
- Continuous pumped‐storage operation results in smaller ebullition than intensive pumping after long‐term storage
- Appropriate management strategies can contribute to a reduction of greenhouse gas emissions from reservoirs
Open accessBaseflow Age Distributions and Depth of Active Groundwater Flow in a Snow‐Dominated Mountain Headwater Basin
-  18 November 2020
Key Points
- Gas tracer data in baseflow that indicate deeper flows through bedrock are an important source to steep, mountain streams
- Historical variability in baseflow age (3–12 years) is dictated by interflow with groundwater contributions stable (11.8 ± 0.7 years)
- Precipitation defines groundwater age sensitivity with flow paths getting deeper and older in a slightly drier future
full accessUnderstanding the Asymmetry of Annual Streamflow Responses to Seasonal Warming in the Western United States
-  17 November 2020
Key Points
- Streamflow responses to warm versus cool season warming for four major Western United States basins are mostly consistent across four models
- Evapotranspiration to temperature sensitivity dominates the asymmetry of streamflow reductions under warm versus cool season warming
- Differences in the basins' runoff responses to seasonal warming are mainly associated with seasonal gross incoming water and temperature
Open accessModeling the Unfrozen Water Content of Frozen Soil Based on the Absorption Effects of Clay Surfaces
-  17 November 2020
Key Points
- The presence of unfrozen water is explained by surface effects, adsorption forces, and the nature of the electrical double‐layer solution
- The surface effects are defined as the combined actions of molecules and negative charges on the clay surface
- The residual unfrozen water is a stable adsorption‐layer solution
full accessSpatial Distribution and Scaling Properties of Lidar‐Derived Snow Depth in the Extratropical Andes
-  17 November 2020
Key Points
- We present the first analysis of snow depth distribution in the extratropical Andes using high‐resolution lidar measurements
- Multiscale behavior in snow depth is found, and fractal parameters depend on local topography and vegetation rather than climate
- The magnitudes of scale break lengths are related to the mean separation distance between local snow depth peaks
full accessHigh Sensitivity of Lake Hypoxia to Air Temperatures, Winds, and Nutrient Loading: Insights From a 3‐D Lake Model
-  16 November 2020
Key Points
- 3‐D ecosystem modeling of a Great Lake showed high sensitivity of hypoxia to climatic air temperature and wind speed variations
- Anoxia (<1 mg O2/L) was even more sensitive than hypoxia (<2 mg O2/L)
- Effects of future temperatures and winds may imply a need for further nutrient reduction approaching 50% beyond current remediation targets
full accessShort‐Term Environmental Flow Assessment of a Functional Estuarine Tidal Flat Ecosystem: A Nonlinear Ecological Response to Flow Alteration
-  16 November 2020
Key Points
- A change in flow discharge alters the sediment deposition rate and induces a state transition of the estuarine tidal flat ecosystem
- Erosion increases the threshold value of flow discharge at which a patterned state occurs
- Our model provides an insightful method with a strong mechanistic basis to assess environmental flow in estuarine tidal flats ecosystems
full accessPartitioning of Historical Precipitation Into Evaporation and Runoff Based on Hydrologic Dynamics Identified With Recent SMAP Satellite Measurements
-  16 November 2020
Key Points
- A large amount of hydrologic information is encoded within satellite remote sensing observations of soil moisture
- SMAP‐era soil moisture and precipitation information, without reliance on models, can characterize landscape hydrological partitioning
- Historical remote sensing and precipitation‐based drainage estimates closely track streamflow measurements across the United States
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Multiscale smoothed particle hydrodynamics model development for simulating preferential flow dynamics in fractured porous media
-  17 December 2020
Key Points
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We developed a new SPH approach to study variably saturated flow in fractures adjacent to a porous matrix.
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We coupled the Navier–Stokes and Richards equations to study gravity‐driven flow and matrix imbibition dynamics.
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We validated the model via laboratory experiments and study the effect of ponding on preferential flow dynamics in porous‐fractured media.
full accessCharacterizing Physical Properties of Streambed Interface Sediments using In Situ Complex Electrical Conductivity Measurements
-  17 December 2020
Key Points
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Complex electrical conductivity can advance the characterization of shallow streambed sediment physical properties such as surface area.
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Surface water layer depth and electrical conductivity only weakly influence the imaginary part of this complex conductivity measurement.
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High surface area iron oxides at anoxic groundwater discharge zones are mapped with imaginary conductivity along one river corridor.
full accessInverse estimation of spatiotemporal flux boundary conditions in unsaturated water flow modeling
-  16 December 2020
Key Points
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Spatiotemporal top flux is inversely estimated in unsaturated water flow modeling from soil moisture dynamics using Tikhonov regularization.
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oWhen top fluxes vary with time only (special case), the inversion reduces to be well‐posed and is explicitly solved without regularization.
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oThe method's performance is evaluated by synthetic data and its applicability in the special case is further verified in field examples.
full accessCombined modelling of US fluvial, pluvial and coastal flood hazard under current and future climates
- Paul D. Bates
- Niall Quinn
- Chris Sampson
- Andrew Smith
- Oliver Wing
- Jeison Sosa
- James Savage
- Gaia Olcese
- Jeff Neal
- Guy Schumann
- Laura Giustarini
- Gemma Coxon
- Jeremy R. Porter
- Mike F. Amodeo
- Ziyan Chu
- Sharai Lewis‐Gruss
- Neil B. Freeman
- Trevor Houser
- Michael Delgado
- Ali Hamidi
- Ian Bolliger
- Kelly McCusker
- Kerry Emanuel
- Celso M. Ferreira
- Arslaan Khalid
- Ivan D. Haigh
- Anaïs Couasnon
- Robert Kopp
- Solomon Hsiang
- Witold F. Krajewski
-  16 December 2020
Key points
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First complete high resolution flood hazard analysis of conterminous US flood risk from all major sources (fluvial, pluvial and coastal).
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In validation tests the model achieved Critical Success Index scores of 0.69‐0.82, similar to many local custom‐built 2D models
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By 2050, flood hazard increases for the Eastern seaboard and Western states, but decreases or changes little for the centre and South‐West
full accessA Self‐Calibration Variance‐Component Model for Spatial Downscaling of GRACE Observations Using Land Surface Model Outputs
-  16 December 2020
Key Points
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A self‐calibration variance‐component model for spatial downscaling of GRACE total water storage
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Generation of high‐resolution total water storage by combination of GRACE observations and land surface model outputs
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Evaluation of groundwater storage monitoring with GRACE observations
full accessThe Effect of Biofilms on Turbulent Flow over Permeable Beds
- Farzan Kazemifar
- Gianluca Blois
- Marcelo Aybar
- Patricia Perez Calleja
- Robert Nerenberg
- Sumit Sinha
- Richard J. Hardy
- Jim Best
- Gregory H. Sambrook Smith
- Kenneth T. Christensen
-  14 December 2020
Key Points
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The effect of presence of biofilm on turbulence in the free flow is due to a combination of reduced bed porosity and change in geometry and roughness.
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Presence of biofilm increases Reynolds stresses in the outer layer scaling with wall shear stress.
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Presence of biofilm dampens dimensionless Reynolds stresses in the vicinity of the permeable bed.
Open accessFactors determining the natural fresh‐salt groundwater distribution in deltas
-  14 December 2020
Key Points
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Global sensitivity analysis of a three‐dimensional, variable‐density groundwater model with complex paleo‐hydrological boundary conditions
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The wide range of geometries, hydrogeological parameterizations and boundary conditions are representative for many deltas worldwide
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Results suggest that fresh‐salt groundwater distributions are not in dynamic equilibrium in at least half of the real‐world cases analyzed
Open accessComment on Dong and Ochsner (2018): “Soil Texture often Exerts stronger Influence Than Precipitation on Mesoscale Soil Moisture Patterns”
-  14 December 2020
Key points
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Dong and Ochsner (2018) concluded that soil texture exerted a stronger influence on mesoscale soil moisture variability than precipitation.
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Dong and Ochsner (2018) made a mistake in their calculation of volumetric soil moisture.
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We found that correlations between soil moisture and soil texture and precipitation were significantly different in only 8 of 18 surveys.
Open accessAn Interannual Probabilistic Assessment of Subsurface Water Storage Over Europe, using a Fully Coupled Terrestrial Model
-  14 December 2020
Key Points
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Terrestrial systems modeling gives an interannual probabilistic assessment of subsurface water storage.
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The hindsight water storage assessment of the drought years 2011/12 and 2018/19 provided useful results.
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The assessment can generate valuable information for pronounced dry and also wet anomalies of subsurface water storage.
Open accessDirect Observation of the Depth of Active Groundwater Circulation in an Alpine Watershed
-  14 December 2020
Key Points
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The depth of active groundwater circulation is a fundamental characteristic of mountain watersheds, yet is rarely well constrained.
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Hydrogeologic, groundwater chemistry, and 3H/3He age data were collected at discrete depths from two boreholes 46 and 81 m deep.
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Borehole data combined with shallow groundwater data and numerical modeling indicate an active circulation depth of ∼20 m.
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A new model for predicting the hydraulic conductivity of unsaturated porous media
- Water Resources Research
-  513-522
-  June 1976
free accessEvaluating the use of “goodness‐of‐fit” Measures in hydrologic and hydroclimatic model validation
- Water Resources Research
-  233-241
-  1 January 1999
Electromagnetic determination of soil water content: Measurements in coaxial transmission lines
- Water Resources Research
-  574-582
-  June 1980
free accessResponse of mean annual evapotranspiration to vegetation changes at catchment scale
- Water Resources Research
-  701-708
-  1 March 2001
Validity of Cubic Law for fluid flow in a deformable rock fracture
- Water Resources Research
-  1016-1024
-  December 1980
Effective and efficient global optimization for conceptual rainfall‐runoff models
- Water Resources Research
-  1015-1031
-  April 1992
Techniques of trend analysis for monthly water quality data
- Water Resources Research
-  107-121
-  February 1982
Open accessThe Millennium Drought in southeast Australia (2001–2009): Natural and human causes and implications for water resources, ecosystems, economy, and society
- Albert I. J. M. van Dijk
- Hylke E. Beck
- Russell S. Crosbie
- Richard A. M. de Jeu
- Yi Y. Liu
- Geoff M. Podger
- Bertrand Timbal
- Neil R. Viney
- Water Resources Research
-  1040-1057
-  6 February 2013
Key Points
- Drivers and impacts of Australia's record drought were analyzed
- Impacts accumulated and propagated through the water cycle at different rates
- Future droughts may not be managed better than past ones.
Developing joint probability distributions of soil water retention characteristics
- Water Resources Research
-  755-769
-  May 1988
free accessAccuracy of scaled GRACE terrestrial water storage estimates
- Water Resources Research
-  27 April 2012
Key Points
- We present gridded gain factors and error maps for GRACE
- Measurement and leakage errors are taken into account
- The new method does not require the use of spherical harmonics by the users
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free access
Water management: Current and future challenges and research directions
- Water Resources Research
-  4823-4839
-  20 June 2015
free accessA multiresolution index of valley bottom flatness for mapping depositional areas
- Water Resources Research
-  16 December 2003
free accessMethods and technologies to improve efficiency of water use
- Water Resources Research
-  29 July 2008
Open accessThe Millennium Drought in southeast Australia (2001–2009): Natural and human causes and implications for water resources, ecosystems, economy, and society
- Albert I. J. M. van Dijk
- Hylke E. Beck
- Russell S. Crosbie
- Richard A. M. de Jeu
- Yi Y. Liu
- Geoff M. Podger
- Bertrand Timbal
- Neil R. Viney
- Water Resources Research
-  1040-1057
-  6 February 2013
Key Points
- Drivers and impacts of Australia's record drought were analyzed
- Impacts accumulated and propagated through the water cycle at different rates
- Future droughts may not be managed better than past ones.
Open accessQuantifying renewable groundwater stress with GRACE
- Alexandra S. Richey
- Brian F. Thomas
- Min‐Hui Lo
- John T. Reager
- James S. Famiglietti
- Katalyn Voss
- Sean Swenson
- Matthew Rodell
- Water Resources Research
-  5217-5238
-  16 June 2015
Key Points:
- Renewable groundwater stress is quantified in the world's largest aquifers
- Characteristic stress regimes are defined to determine the severity of stress
- Overstressed aquifers are mainly in rangeland biomes with some croplands
free accessRelationships between Pacific and Atlantic ocean sea surface temperatures and U.S. streamflow variability
- Water Resources Research
-  19 July 2006
free accessThe science and practice of river restoration
- Water Resources Research
-  5974-5997
-  24 July 2015
Key Points
- River restoration is a prominent area of applied water‐resources science
- restoration includes connectivity, physical‐biotic interactions, and history
- effective restoration requires collaboration among scientists and practitioners
free accessThe twenty‐first century Colorado River hot drought and implications for the future
- Water Resources Research
-  2404-2418
-  17 February 2017
Key Points
- Record Colorado River flow reductions averaged 19.3% per year during 2000–2014. One‐third or more of the decline was likely due to warming
- Unabated greenhouse gas emissions will lead to continued substantial warming, translating to twenty‐first century flow reductions of 35% or more
- More precipitation can reduce the flow loss, but lack of increase to date and large megadrought threat, reinforce risk of large flow loss
Plain Language Summary
Between 2000 and 2014, annual Colorado River flows averaged 19% below the 1906–1999 average, the worst 15‐year drought on record. Approximately one‐third of the flow loss is due to high temperatures now common in the basin, a result of human caused climate change. Previous comparable droughts were caused by a lack of precipitation, not high temperatures. As temperatures increase in the 21st century due to continued human emissions of greenhouse gasses, additional temperature‐induced flow losses will occur. These losses may exceed 20% at mid‐century and 35% at end‐century. Additional precipitation may reduce these temperature‐induced losses somewhat, but to date no precipitation increases have been noted and climate models do not agree that such increases will occur. These results suggest that future climate change impacts on the Colorado River will be greater than currently assumed. Reductions in greenhouse gas emissions will lead to lower future temperatures and hence less flow loss.
Open accessA Transdisciplinary Review of Deep Learning Research and Its Relevance for Water Resources Scientists
- Water Resources Research
-  8558-8593
-  30 August 2018
Key Points
- Deep learning (DL) is transforming many scientific disciplines, but its adoption in hydrology is gradual
- DL can help tackle interdisciplinarity, data deluge, unrecognized linkages, and long‐standing challenges such as scaling and equifinality
- The new field of AI neuroscience opens up many opportunities for scientists to use DL as an exploratory tool for scientific advancement
free accessHillslope Hydrology in Global Change Research and Earth System Modeling
- Y. Fan
- M. Clark
- D. M. Lawrence
- S. Swenson
- L. E. Band
- S. L. Brantley
- P. D. Brooks
- W. E. Dietrich
- A. Flores
- G. Grant
- J. W. Kirchner
- D. S. Mackay
- J. J. McDonnell
- P. C. D. Milly
- P. L. Sullivan
- C. Tague
- H. Ajami
- N. Chaney
- A. Hartmann
- P. Hazenberg
- J. McNamara
- J. Pelletier
- J. Perket
- E. Rouholahnejad‐Freund
- T. Wagener
- X. Zeng
- E. Beighley
- J. Buzan
- M. Huang
- B. Livneh
- B. P. Mohanty
- B. Nijssen
- M. Safeeq
- C. Shen
- W. van Verseveld
- J. Volk
- D. Yamazaki
- Water Resources Research
-  1737-1772
-  27 February 2019
Key Points
- Lateral flow from ridges to valleys, and contrasts between sunny and shady slopes organize water, energy and vegetation across landscapes
- These processes may affect Earth System Model predictions of terrestrial water storage and fluxes, as well as ecosystem resilience to stress
- The greatest knowledge gap is the subsurface structure; Critical Zone science can offer new insights into terrestrial water storage/fluxes
Plain Language Summary
Hillslopes are key landscape features that organize water availability on land. Valley bottoms are wetter than hilltops, and sun‐facing slopes are warmer and drier than shaded ones. This hydrologic organization leads to systematic differences in soil and vegetation between valleys and hilltops, and between sunny and shady slopes. Although these patterns are fundamental to understanding the structures and functions of water and terrestrial ecosystems, they are too fine grained to be represented in global‐scale Earth System Models. Here we bring together Critical Zone scientists who study the interplay of vegetation, the porous upper layer of the continental crust from vegetation to bedrock, and moisture dynamics deep into the weathered bedrock underlying hillslopes and Earth System Model scientists who develop global models, to ask: Do hillslope‐scale processes matter to predicting global change? The answers will help scientists understand where and why hillslopes matter, and to better predict how terrestrial ecosystems, including societies, may affect and be affected by our rapidly changing planet.